X Window System

X Window System
	twm, the default X11 window manager
Original author(s)	Project Athena
Developer(s)	X.Org Foundation
Initial release	June 1984
Stable release	X11R7.7 / 6 June 2012
Operating system	Unix, Unix-like, MVS OpenVMS, DOS
Platform	Cross-platform
Predecessor	W Window System
Type	Windowing system
License	MIT License
Website	www.x.org

The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems.

X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984.^[3] The X protocol has been at version 11 (hence "X11") since September 1987. The X.Org Foundation leads the X project, with the current reference implementation, X.Org Server, available as free and open-source software under the MIT License and similar permissive licenses.

^ "7.7". Retrieved 5 April 2024.
^ "X11R7.x - X Window System Version 11 Release 7.x ongoing development". Retrieved 5 April 2024.
^ Steiner, Jennifer G.; Geer Jr., Daniel E. (21 July 1988). "Network Services in the Athena Environment". Proceedings of the Winter 1988 Usenix Conference. CiteSeerX 10.1.1.31.8727.